Heat-treating apparatus



Jan. 7, 1947.

G. J. MAXSON HEAT TREATING 'APPARATUS Filed Jan. 1o. 1942 2 Sheets-Sheet 2 Patented Jan. 7, 1947 y `nnA'r-'rREA'nara APPARATUS Gordon J. Maxson, Western Springs. Ill., assigner to Western Electric Company, Incorporated, NewgYork, N. Y., a corporation of New York Application January 1o, 1942,'seria1 Nq. 426,362

1s claims'. (c1. 26e-4) This invention relates to a heat treating apparatus and more particularly to an apparatus in which parts may be brazed, hardened and annealed in a prepared atmosphere.

It is an object of the present invention to provide a relatively simple heat treating apparatus in which parts may be brazed or heat treated and quenched either in a quenching bath or a prepared atmosphere quenching area,

In accordance with one embodiment of the invention, a heat treating furnace lis provided wherein the heating area is sealed from the outside atmosphere and supplied with a prepared atmosphere and has positioned directly beneath it a cooled chamber, also sealed from the outside atmosphere and in communicationwith the furnace, so that gas supplied to the furnace will pass through the cooled area.- The cooled portion of the apparatus vextends down to a liquid quench which is positioned in the bottom portion of the cooling vchamber whereby parts may be lowered directly from the furnace in which they are heated, through the cooled chamber, to the quenching bath without leaving the controlled atmosphere.

In the specific embodiment of the invention disclosed herein, a water :lacketed cooling chamber is in` communication with the heating chamber and a prepared atmosphere, preferably nitrogen, is forced into the upper portion of the heating chamber down through the cooling chamber and back to a source of supply or a circulating niechanism, which will continuously circulate the prepared atmosphere through the furnace. The area in which parts may be cooled is provided with a door which effectively seals this area and which may be removed to permit parts to be loaded on to a lifting platform movable from the heating chamber to the quenching bath directly beneath the chamber, whereby parts may be supported in the heating chamber, the cooling chamber, and/or the quenching bath. A

A better understanding o! the invention may be had by reference to the accompanying drawings, wherein I y Fig. 1 is a plan view of the heat treating apparatus constituting one embodiment of the invention;

Fig. 2 is a vertical sectional view 4taken substantially on the line 2--2 ofV Fig. 1 in the `direction `oi' the arrows, showing the details of construction of the article supporting platform and its elevating mechanism and the relative location of the heating chamber, cooling chamber and` quenching bath;

Fig. 3 is a horizontal sectional view taken along the line 3-3 of Fig. 2 in the direction of the arrows showingthe arrangement of heating units within the heating chamber, and

Fig. 4 is a horizontal sectional view taken along the line 4-4 of Fig. 2 in the direction of the arrows showing the relative position of the cooling chamber and charging door, whereby parts may be placed in the apparatus.

Referring to the drawings, wherein like reference characters designate the same parts throughoutthe several views, particular reference being had to Figs. 1 and 2, wherein a framework 9, comprised of a plurality oi' angle members, supports the furnace. `Verticaily extending angle members III-I0, extending upwardly from suitable base members II-I I. are disposed ,about a quench tank I2 and carry, at

their upper ends, horizontally extending angle members I3I3, on which there are supported a pair of transverse plates I4-I4, which structure makes up the supporting framework for the vupper portions of the apparatua The quench tank I2, which is cylindrical in shape, is provided with an inlet pipe I5 .and an outlet pipe I6, whereby a supply of quenching material I may be circulated and supplied to the quench tan-k I2. Se-

' may` be supported.

The cooling chamber I9 comprises inner and outer walls 20and 2|, which define the limits of a water Jacket or compartment 22, in which a cooling fluid may be circulated. The compartment 22 may be supplied with a cooling iluid through an inlet pipe 23 and an outlet pipe 2l is provided for directing the cooling fluid back to a circulating system of any suitable type (not shown)- The cooling chamber I3 is provided with a door 30 hinged to the main portion of the chamber I3 by means of hingesu3i and 32. This door 30 is hollow and may be connected to the same cooling system as 4the chamber 22 by inlet and outlet ports 33 and 34, suitable flexible connections (not shown) being provided for connecting theinlet and outlet ports 23 and 24 and 33 and 34 to the coolant circulating system. In order to eiect an air tight seal between the door 30 and the remainder of the cooling chamber I9, lock bolts 35 and 36 are pivoted at 31 and Threaded on the forward end of the lock bolts 35 and 35 are hand wheels 4| and 42, respectively, which may be run down on the threads of the bolts 35 and 33 to .engage slotted flange members 43 and 44, respectively, thus to tightly clamp the door of the cooling chamber to the main portion thereof. Positioned in the center of the door 30 is a window 45, set into a collar 46 extending through the door 30, whereby parts in the furnace may be inspected without opening the door.

The upper end of the cooling chamber I9 is suitably connected, as by welding, to plates 50 and I, which arebent downwardly at their outer ends to form a flange against which end members 52 and 53 are fixed. The plates 50 and 5| and end members 52 and 53 cooperate with an annular casing member 54 to provide a door receiving compartment into which doors 55 and 51 of heat insulating material may be moved. The doors 55 and 51 are provided at their rear ends with threaded members 58 and 59 and have apertures 50 and 6| formed therein in alignment with the threaded members 58 and 59 for receiving oppositely threaded portions of a door actuating screw 62. The screw 62 is journalled in a bearing member 63, at the right side of the apparatus (Fig. 2), which bearing member is mounted on the plate 52 and at the left side of the apparatus (Fig. 2), the screw member 52 is :lournalled in a bearing 65. The screw 62 has mounted on its left end a driving Sheave 56, which is adapted to be driven by a motor 51 through a belt 58 to open or close the doors 56 and 51.

The casing-member 54 has mounted on it a tubular shell 10, the upper end of which is closed by means of a plate 1| resting on a. flange 12 formed integrally with the tubular member 10. Surrounding the member 10 and resting upon the casing member 54 is a tubular body of insulating material 13, and within the tubular member 10 there are placed a series of refractory members 15, which cooperate to form a cylindrical heating chamber and which are cut away along their inner edges, as shown at 11, to receive a heating element 16, which is bent to form an irregularly shaped coil extending all the way around the inside of the chamber defined by the refractory members 16. At their upper ends, the refractory members 16 are cut away so that several folds of the heating element may be formed adjacent the upper end of the heating chamber. Similarly, alternate ones of the members 16 are cut away, as shown at 80. to receive several folds of the heating element 18. In this manner, the upper and lower areas of the furnace heating chamber which are not heavily insulated will have a larger amount of heating element therein than the central area thereof so that an even temperature may be maintained in the heating chamber defined by the refractory member 16.

The upper end of the refractories 15 have a circular cap member 82 positioned thereon to, prevent any substantial amount of heat from escaping from the heating chamber. The cap member 82 has a central aperture 83 formed therein to permit the passage therethrough of a platform supporting chain 84, the upper end of which passes around a sheave 95 adapted to be driven through a belt and pulley connection 35 by a motor 81, transmitting power through speed reducer 88.- The shaft on which the sheave 85 is mounted is positioned in a housing 90, sealed to the plate 1I and the shaft is properly hushed t0' prevent the escape of gas from the housing 9|. The housing 0I is provided with an inlet port 92, whereby a gas, preferably nitrogen, may be supplied to the furnace to maintain a controlled atmosphere therein. Extending through the plate 1I and cap member 82 is a thermocouple 94 for controlling the temperature of the heat treating chamber defined by the refractory members 15. Articles to be heat treated in the apparatus may be positioned vtherein through the door and may be placed upon a perforated platform 95 having a bail structure 98 connected thereto and to the platform elevating chain 04. Any gas admitted to the housing 90 will pass therethrough, through the aperture 83, through an aperture |00 formed by cooperating walls of notches cut in the inner ends of the doors 58 and 51 and thence down into the cooling chamber I9, from which the gas may pass through an outlet |02 to a suitable circulating system for preparing a desirable gaseous atmosphere for use in heat treating parts in the furnace.

Inthe operation of the apparatus, the doors 56 and 51 may be retracted into the compartment formed by the members 52 and 53 and the casing member 54 by supplying current to the motor 61 for rotating the screw 52 in the proper direction. After the doors 55 and 51 have been opened, the platform 96 may be lowered to position Just below the door 30 and the door may be removed by manipulating the hand wheels 4| and 42 and the lock bolts 35 and 35 to permit the parts to be heat treated to be placed on the platform, whereupon the platform may be elevated to the position shown in Fig. 2, the door 30 closed and clamped in place on the cooling chamber I3 and `the apparatus started in operation by supplying current to the heating element 18 and controlling the heat generated by these elements through thethermocouple 82. When the apparatus is started in operation, a prepared gas may be supplied to the apparatus through the inlet port 92. This gas may be circulated through the apparatus, passing first through the aperture 88 into the chamber, deflned'by the refractories 16, thence to the aperture |00 and to the air quenching area or chamber I9 and out through the outlet port |02. Suitable systems for generating a gas constituting a desired controlled atmosphere are disclosed in the co-pending applications of G. J. Maxson, Serial No. 426,367, filed January l0, 1942, and A. W. Laird and G. J. Maxson, Serial No. 426,368, flied January 10, 1942. The gas prepared in systems such as these may be circulated through the apparatus repeatedly, the quenching bath I1 serving as a seal for the lower end of the apparatus and the upper end of the apparatus being closed to the outside atmospherelby the tubular shell 10 and housing 90.

If it is desired to quench the treated articles or parts in a bath, the bath I1, which may be continuously circulated through the inlet andl outlet ports I3 and |5, provides a suitable quench to which parts may be directed by the platform 96 under actuation by the motor 83 and if it is desired to quench the articles in the controlled atmosphere, this may be done in the chamber I8, which is supplied with a coolant circulated therethrough through the ports 23, 24, 33 and 34, it simply being necessary to close the doors 55 and 51 after parts have been passed into the cooling chamber i9 or quench bath I1, whereby thev heat of the furnace will be substantially cut off from the cooling bath or chamber while the controlled atmosphere may be circulated through the system. 'Thus'. articles to be heat treated may be either quenched in a controlled atmosphere or in a quenching bath without coming in contact with the outside atmosphere and the controlled atmosphere may be conserved, making it possible to use treating atmospheres -which `heretofore were too expensive for commercial use. With theY than the air. This process is further aided' by feeding the prepared atmosphere in at the top of the furnace, eliminating the necessity of purging the heating chamber each time the door is opened to load the work on the platform 86.

What is claimed is: 1. An apparatus for treating `articles comprischamber in communication with the heat treating chamber, a door in said gas quenching chamy ber, a liquid quenching chamber in communication with the gas quenching chamber and sealed to the .bottom of said gas quenching chamber, means for receiving parts passed through said door for supporting the parts selectively in any of said chambers, doors interposable betweenthe heating chamber and gas quenching chamber for preventing any substantial amount of heat from passing from the heating chamber to the gas quenching chamber during the quenching of parts, compartments sealed from the outside atmosphere'and in communication with the chaming a heat treating chamber, a gas quenching chamber in communication with the heat treating chamber, a door in saidgas quenching chamber, `a liq'uid quenchingl chamber in communication with the gas quenching'chamber and sealed to the bottom of said gas quenching chamber, and means for receiving parts passed through said door for supporting the parts selectively in any of said chambers.

2. An apparatus for treating articles comprising a heat treating chamber, a gas quenching chamber in communication with the heat treating chamber, a door in said gas quenching chamber, a liquid quenching chamber in communication with the gasfquenching chamber and sealed to the bottom of sa'id gas quenching chamber, means for receiving parts passed through said door for supporting the parts selectively in any of said chambers, and means operable to move said supporting means into any of the chambers.

3. An apparatusfor treating articles comprising a heat treating chamber, a gas quenching chamber in communication with the heat'treating chamber, a door in said gas quenching chamber, a liquid quenching chamber in communication with thev gas quenching chamber and sealed to the bottom of said gas quenching chamber,

' means for receiving parts passed through said door for supporting the parts selectively in any of said chambers, and doors interposable between the heating chamber and gas quenching chamber for preventing any substantial amount of heat from passing from the heating chamber to the gas quenching chamber during the quenching of parts.

4. An `apparatus for treating articles comprising a heat treating chamber, a gas quenching chamber in rcommunication with the heat treating chambena door in said gas quenching chamber, a liquid quenching chamber in communication with the gas quenching chamber and sealed4 to the bottom of said gas quenching chamber, means for receiving parts passed through said door for supporting the parts selectively in any of said chambers, doors interposable between the heating chamber end gas quenching chamber for preventing any substantial amount of heat from passing from the heating chamber to the gas quenching chamber during the quenchingi of parts, and compartments sealed from the outside atmosphere and in communication with the chambers of the apparatus for receiving said doors when the doors are opened to permit passage of the article support from the heating chamber to the quenching chamber.

5. An apparatus for treating articles comprising a heat treating chamber, a gas quenching bers of the apparatus for receiving said` doors when the doors are opered to permit passage of the article support from the heating chamber to the quenching chamber, and means forjactuating said doors.

6. An apparatus, for treating articles comprising a heat treating chamber, a, gas quenching chamber in communication with the heat treating chamber, a door in said gas quenching chamber, a liquid quenching chamber in communicationwith the gas quenching chamber and sealed to the bottoni` of said gas quenching chamber, means for receiving parts passed through said door for supporting the parts selectively in any of said chambers, doors interposable between the heating chamber and gas quenching chamber for preventing any substantial amount of heat from passing from the he ting chamber to I the gas quenching chamber dur ng the quenching of parts, compartments sealed from the outside atmosphere and in communication with the chambers of the apparatus for receiving said doors when the doors are opened to permit pas- -sage of the article support fromA the heating -chamber to the quenching chamber, and a passage formed by cooperating portions of said doors to permit passage of gas from the heating chamber to the gas quenching chamber.

'1. An apparatus for treating articles comprising a heat treating chamber, a gas quenching chamber in communication with the heat treating chamber, a door in said gas; quenching chamber, a liquid quenching chamber in communication with the gas quenching chamber and sealed to the bottom oi' said gas quenching chamg ber, means for receiving parts passed through said door for supporting the parts selectively in any of said chambers, means operable to move said supporting means into any of the chambers, and a housing in communication with the heating chamber for enclosing a portion of thev support actuating means.

8. An apparatus for heat treating articles in a nitrogen atmosphere comprising a vertically disposed heating chamber having an inlet port at its upper end, a gas quenching chamber sealed to and disposed directly beneath the heating chamber, a quench tank sealed to and disposed directly beneath the gas quenching chamber, a loading door in said gas quenching chamber, and a gas outlet port in said gas quenching chamber.

9. An apparatus for heat treating articles in a nitrogen atmosphere comprising a vertically disposed heating chamber having an inlet port at its upper end, a gas quenching chamber sealed to and disposed directly beneath the heating chamber, a quench tank sealed to and disposed directly beneath the gas quenching chamber, a loading door in said gas quenching chamber, and a gas outlet port adjacent the seal between the sas quenching chamber and quench tank to withdraw the gas from the bottom of the gas quenching chamber.

10. An apparatus for heat treating articles in a nitrogen atmosphere comprising a vertically disposed heating chamber having an inlet port at its upper end, a gas quenching chamber sealed to and disposed directly beneath the heating alignment, a bottom loading furnace, a charging chamberhaving closure means for the admission of work to be treated, and a quenching bath, and means for transferring work from said charging chamber into the furnace and after heat treatment', into said quenching bath.

12. A heat treating apparatus comprising a bottom loading furnace, a charging chamber positioned beneath said furnace, a quenching bath positioned beneath said charging chamber, said furnace, chamber and bath being in vertical alignment, and transfer means for moving articles from the furnace through the charging chamber to the quenching bath.

13. A heat treating apparatus comprising a bottom loading furnace, a charging chamber positioned beneath said furnace, a quenching b ath positioned beneath said charging chamber, and transfer means selectively operable to position articles in the furnace, chamber or bath.

14. A heat treating apparatus comprising a bottom loading furnace, a charging chamber positioned beneath said furnace, a closure means in said charging chamber for the admission of work to be treated, a quenching bath positioned beneath said charging chamber, and means for transferring work selectively from the charging chamber to the furnace and from the furnace to the bath.

15. A heat treating apparatus comprising a bottom loading furnace, a charging chamber positioned beneath said furnace, acharging door in said charging chamber for the admission of work to be treated, a quenching bath positioned be- 8 4 neath said charging chamber, and means for transferring work selectively from the charging chamber to the furnace and from the furnace to the bath, said furnace, charging chamber and bath being in direct communication and sealed relation one to another.

16. A heat treating apparatus comprising a bottom loading furnace. a charging chamber positioned in direct vertical alignment beneath the furnace, a quenching bath positioned in direct vertical alignment with the charging chamber, said furnace chamber and bath being in sealed communication one 'with the other, transfer means for transferring articles to be treated from one to another chamber and bath, and means for introducing treating gas into the furnace and directing it through the furnacefto the charging chamber.

17. A heat treating apparatus comprising a bottom loading furnace, a charging chamber pcsitioned in direct vertical alignment beneath the furnace, a quenching bath positioned in direct vertical alignment beneath the charging chamber, said furnace chamber and bath being in sealed communication one with the other, transfer means for transferring articles to be treated from one to another of the chamber, furnace and bath, means for introducing treating gas to the upper end of said furnace, and an outlet adjacent the bottom of the charging chamber, whereby gas may be forced through the furnace and charging chamber to purge the charging chamber of air admitted during the loading of the furnace.

18. An apparatus for treating articles comprising a heat treating chamber, a charging chamber in communication with the heat treating chamber, a door in said charging chamber, a liquid quenching chamber in communication with the charging chamber and sealed to the bottom of the charging chamber, and means for receiving parts passed through the door for supporting articles selectively in any of the chambers.

GORDON J. MAXSON. 

